Recoilless gun



K. R. FOWLER RECOILLESS GUN July 9, 1957 5 Sheets-Sheet 1 Filed Dec. 12, 1946 KENNETH R FDWL ER,

K. R. FOWLER RECOILLEZSS GUN July 9, 1957 5 Sheets-Sheet 2 Filed Dec. 12, 1946 I I 1 I |L KE NNETH RQFUWLER,

K. R. FOWLER July 9, 1957 RECOILLEISS GUN Filed Dec. 12, 1946 M M M KENNETH R- DWLER,

lnblmm HFLH K. R. FOWLER RECOILLESS GUN July 9, 1957 5 Sheets-Sheet 4 Zlrwwvbwc KENNETH R FUWI ER,

Filed D60. 12, 1946 July 9, 1957 R. FOWLER 2,798,413

RECOILLESS GUN Filed Dec. 12, 1946 5 Sheets-Sheet 5 KENNETHR FUWI ER,

' RECOILLESS GUN Kenneth R. Fowler," Warren, Pa. Application December 12, 1946, Serial No; 715,674

- 4 Claims. (Cl. 891 .7)

' This invention. relates to'improvements. in recoilless weapons, particularly air-cooled single-loadingrec'c'iilless guns for firing fixed ammunition as' distinguishedlfrom those weapons firing rocket-propelled or jet-propelled ammunition.

An object of this invention isto provide a recoilless gun in which parts thereof are readily demountable for transportation and are capable of being quickly assembled. Another object is to provide a recoilless gun-ofglight weight and easy operation with a locking'sleeve carrying an interrupted thread, the sleeve being lighter in weight and easier to rotate and translate than is the gun body of its breechblock. A further object-is to provide a stop for the breechblock when it has been moved froman out-ofthe-way position for loading-to aposition in which it is aligned with the gun axis.

Recoilless guns as a class'are generally of lighter weight than recoil type guns of the same caliber and this-has enabled recoilless guns .to bemore-easily transported. This invention makessuch recoilless guns still more easily transportable by making some 'of their parts easily demountable and readily assembled. To "accomplish this result, the breechblock is easily removable from the gun body-and from an actuating shaft for it. This shaft and also the"trunnions with their band are likewise removable from-the gun body or front gun section. 1 Instead of rotating either the breechblock or gun body preparatory to opening the breech;' asleeveof lighter weight than either the breechblock or gun is providedfwith an interrupt'ed thread engaging a cooperativethread 'on the I breechblock and'this' sleeve isrotated' and then subjected 'to'translation'in order to'release a connection before the -breechblock is movedout of the way. '.Inasmuch as the breeohblock is. heavier than-some other;v gun partsv as 'shown by the drawing, a projection from the sleeve is provided with an interrupted thread and engages the groove between threaded portions of the breechblock to act as a stopandalignthe sleeve and breechblock before the latter issubjectedto arelative rotation forclosingthebreech.

"Ammunitionfor'thepresent type 'of'weapon consists of i This form'of ammunitionr'is described 'in 'copending 'iappli'cation 'Serial-'No: 7'15,'675;'filedDe'cember 12, 1946, for Ammunition if :for Recoilless 1 Gruns, 1 now Patent 2,'492,-279"dated. December 27,1949.

* The-foregoing and other objects of the invention as well -as the exact nature thereof will be apparent by -reference to' the following description of'the accompanying drawings in which:

2,798,413 Patented July 9,. 1957 BQQ Figure 1 is an elevational view of the gunoetach'ed from its mount;

Figure 2 is a longitudinal vertical central sectional view through Figure 1, showing: the gun preparatory-tofiring, loaded with .a round of. ammunition, shown partially in section, and certain of the gun operating parts in sectional .and others in plan views.

"Figure 3 is a view similar to Figure 2, but showing the 1 locking sleeve disengaged from the breechblockprepara- 'tory to opening the same for extracting. an expended round of.'ammunition, shown in section.

Figure 4 is a view similar to Figure 2 but with the breechblock, shown in elevation, opened but n'otyetclear .of the ammunition'chamber.

Figure 5.is a plan view ofFigure 1 but with the breechblock in an open position'clear of the ammunition cham- 1 bet;

"Figure 6-is a transverse section taken on line 6'6V of Figure .2;

Figure 7 is a View similar to Figure 6 but .showingthe ,locking sleeve in a-position preparatory to swinging the breechblock away from the ammunition .chamber;

' Figure 8 is a transverse section throughdine 8+8. of

"Figure ,2;

Figure 9 is a bottom plan view-of the locking sleeve; Figure, 10 is a top .view of the ,operatingmechanism thru line 10- 10 of Figure 3; i

1 Figure 11 is an elevationalview ofthe vventurLorifices of the .breechblock as viewed fromthe.:interior..thereof and through which the propellent gases .escapewtox neutralize recoil of the weapon;

. Figure 12 is a sectional view through line 12-42 of "Figure 11;

Figure 13 is a detailsectional .view .of-theelectrical firing mechanism;

J Figure 14 is a sectional view through .line 14-14 of Figure 10;.and

'Fig. 15 is a section through the breech .enduoftthe. gun of Figs. 2 and 3.

'J'Ehe recoilless-weapon .of theainvention consists generally of a barrel band 1 supporting a frontgumsection .or barrel .2. :having an ammunition chamber 3 closed by a rear section orbreechblock 4 through a lockingssleeve 5 actuated tbyian operating mechanism 6 depending from thebarrel band 1. Asshown in the drawing,the sleeve 5 I is lighter in weight andtherefore easier tovmove thantthe frontor rear gun sections.

The barrel 2 integrally. merges with rthe enlargedtchamher 3 through a sloping portion 7', the chamber-3 being adapted to receive acartridge case 3' of -the.-type:having a. frangible cap-- 4 :and:an-.annular' metallic ring 66 rencircling the rear end portion of the case and insulated' as described: in .copending U; S. :application Serial No.

" 7:l-5, 675,-now Patent 2,492,279 datedDecember. 27,-1949.

llhechamber 3 has an integral circumferential flange 9.,.a.machin ed cylindricalouter surface 10,-and a locking notch 11 in its slope 7. Theifiange 9-has-internally thereof an annular recess 9' forreceiving thenannular.-ring.66 ofthe1cartridge case 3.

Thebarrel 2.. maybe .either smooth-bored orrtrified, either being suitable for use in recoilless weapons oftthe instant type. -However-, practicaltexperience has v.proven that results :obtained with smooth boreubarrels, as to accuracy and range, are. far inferior to the results obtained with rifled barrels s-othatthe .latter are preferred. The periphery of thebarrel 2, adjacent thechamber slope 7, is provided with interrupted threads :12.'(Fig. 2)

for ready removal of the barrel band l'and its'attached shaft. This band 1 has. a cylindrical portion13 with internal interrupted threads 14 for meshing withIthe .external threads 12. 'The top of theeyli'ndrical memher 13,'is provided with an upstanding lug 15, open slotted for receiving a threaded locking screw 16 having a pair of spaced integralcollars 17 Y for straddling the lug 15. The screw 16 is thus held in the lug against axial movement but free to be rotated by a handle 18 pivoted to the screw 16. Y Akey' 19, slidably mounted between a pair ofspaced parallelguides 20, formedrintegral upon the cylindrical portion 13, is threaded to the screw 16.

I The key 19 has a tapered end and, through rotation of the screw 16, can be moved into and out of the tapered notch 11 in the'chamber' slope 7 as shown in Fig. '5; Withdrawal of the key19 fromthenotch 11 frees the barrel band 1 for rotation, to disengage the threads 12 and 14,

and removal from the threaded portion 12 by movement longitudinally and muzzlewardly of the barrel.

Securely attached to the barrel band 1 are diametrically opposite trunnion pins 21 for supporting the gun in any suitable structure. -The end of the key 19 engaging the correctly positioned angularly. Y

Dependingfrom the barrel band 1 is a bracket 22 of I- shaped cross section supporting a longitudinally extend-' a tubular member 24 parallel ing abutment plate 23 and to'the barrel 2. I I

' Y The tubular member 24 has its forward end closed by a threaded cap 25 and its rearward end terminating. in'a downwardlydirected stop member 26 having a radial flange 26' functioning in a manner to be described.

A shaft 27 is slidably and rotatably supported within the tubular member 24. The forward end of the shaft 27 is threaded at 28 to receive a threaded plug 29 having a flange 30'adapted to abut the threaded end 27 to limit excessive sliding movement of the shaft 27 to the rear.

For a purpose to be described, the shaft 27 is provided ment 23. The detent'23' is forced by a spring 23 into engagement with either the slot 29' or the depression 29" for yieldably retaining the shaft 27 in either of two position shown in Figures 3 and 4, respectively.

Anchored to the shaft 27 is a gear case 32 rotatably carrying a cross shaft 33 to which is secured a helical toothed pinion 34 meshing with an L-shaped rack 35 having teeth for cooperation with the pinion 34 and attached to the locking sleeve 5. A hand lever 31 is secured outside of and on the right in Fig. 1 of the gear case 32, it being secured to the cross shaft 33 for rotating the same. Figs. 2, 3, and 4 should not imply that this lever 31 is on the left or opposite side. The hand lever 31 is formed with an oppositely extending lug 31' for coaction with the flanged stop member 26 to prevent rotation of lever 31 when the same is swung fromits Fig. 4 position to that shown in Fig. 5 and intermediate positions.

A shaft 36 is attached to the gear case 32 in alignment with the shaft 27. The shaft 36 is provided with a longitudinally extending rib or tooth 37 and a transverse plate 38 (Figs. 6 and 7). The shaft 36 terminates in an end portion 39, having an open-ended slot 40, for receiving the breechblock disconnect pin 59.

As shown in Figure 9, the locking sleeve 5 is formed with longitudinally spaced cylindrical portions 41, 42 and 43.

The forward cylindrical portion 41 slidably mounts the locking sleeve 5 on the ammunition chamber surface 10 and contains the L-shaped gear 35, having a longitudinal leg 44 and a transverse leg 45, which as previously explained is in mesh with the helical toothed gear 34 in firing position. i

The intermediate cylindrical portion 42' has formed thereon a tapered portion 46 (Fig. l) and a curved depression 46' (Fig. 9) to provide the necessary clearance for the helical toothed pinion 34 and its casing 32 at the end of thetravel of the gear 34 on the longitudinal leg 44. .Motion of the sleeve 5 to the rear of the gun is limited by the internal shoulder 47 abutting the circum ferential flange 9. v

The rearward cylindrical portion 43 is provided on its underside with longitudinal teeth as and 49 (Fig. 9

adapted to engage the tooth 37. The rear end surface ,of the portion43 is provided with: a segmental groove 50 (Fig. 9') extending completely across tooth 49 and partially across tooth 48. A lug 51 (Figs. 1, 6 and 7) projects radially from theperiphery of portion 43 at the end of the segmental. groove 50 and oppositethe tooth Y 48. The teeth 48 andv49, the groove 511 and the lug 51 i side ofthe notch 11 assistsinhaving the trunnion axis cooperate with the longitudinal tooth 37 and transverse plate 38 in a manner to become apparent.

The rear cylindrical portion 43 is provided with an internal interrupted thread 52 (Fig. 4) adapted tov mesh 'with the external interrupted thread 53 on the breechblo'ck4. The. breechblock 4 contains a sleeve 54 in which is a chamber 55 and venturi orifices 56.v Internally threaded rearward projection 52 extends from the sleeve 5 toact as a stop for the breechblock and to assist I in properv engagement by the threads 52 of the sleeveand the interruption of the threads 53 of the breechblock,

when the breechblock or rear gun section is swung back Y from its vposition in Fig. 5 to its position of alignment with the front gun section ,3.

' vAs shown in Figures 2, 11 and 12, each orifice 56 is A 1 formed from a pair of frusto-conical portions connected together end-to-end at their smaller bases to form a con-.

tinuous passage for the discharge of the propellent gases. Each orifice as a unit is displacedina direction opposite Y a bore 58 through which bracket 57-is rotatably mounted upon the slottedportion 39 of the shaft 36. w v

which the shaft 59 can be slid into final position in the shaft opening 40 and locked therein by rotating the hand lever 61 from a position fore-and-aft of the weapon to an upright position shown in the drawings (Fig. 14). A firing mechanism, generally indicated by reference numeral 62, is of the electrical contact type fed through a lead 65 from an electrical source, not shown, and having a plunger 63 forced by a coiled spring 64 into contact with the insulated ring 66 of a round of ammunition for electrically exploding the same in a manner explained in the previously mentioned co-pending application Serial No. 715,675, now Patent 2,492,279 dated December 27, 1949.

Operation In Figures 1 and 2, the gun is shown with breechblock 4 in closed position preparatory to firing of the weapon. Upon ignition of the propellent charge, the projectile is projected forwardly out of the barrel and the frangible head 4' is disintegrated, allowing a portion of the propellent gases to be discharged rearwardly through the breechblock and out the venturi orifices 56.

The propellent gases passing rearwardly through the orifices 56 create a force in a direction to counteract the recoil caused by the projectile in being propelled from the gun. Also due to the inclination of the orifices 56 the thrust of the escaping propellent gases will be in such direction as to offset the tendency of the rifled barrel to twist in a direction opposite to the rotation of the projectile as it advances through the barrel. Obviously, the barrel may be rifled with a left or right hand twist and rotational reaction could be eliminated in either case by directing the inclination of the orifices in the opposite direction. Hence, the orifices counteract both the recoil and rotational reactions of the barrel caused by the longitudinal and the rotational movement of the projectile as it is 'propell'ed' through the'barrel. The orifices not only counteract the twisting reaction of the barrel, "butalso exert a turning'action' uponthe'breechblock itself to maintain= itin its locked po'sition during firing.

The-breechblo'ck' 4- is open'ed (onunlocked) by turning the hand lever- 31 clockwise, indicated by the arrow in -Figure 1. i This will rotate thehelical-toothed pinion 34, in mesh'-' with the transverse leg 45 I of the- L shaped gear 1 sector 35, which in turnwill rotate the looking I sleeve ina clockwise"dire'ction--as' viewed"in Figure 8; 'for ----approximately Msof arevo1ution-' to disengage the interru'pted threads--53 and -52, at which time the longer-tooth 48- on' the'locking sleeve 5" will-strike the tooth 37"on "theshaft 36 to -hold the locking sleeve 5 against further "clockwisemovementy'as-viewed -in Figures 7 and 8, or -angular downward movementas viewed in Figure 1. During the above operation, 'the shaft '27, and conse- -'-quently"-the*=gear -34 and -the-shaft"36 are held from movement totherear'by the spring pressed deten t 23"'engaging *"the depression '29".

As the locking sleeve 5 is restrained from rotation due to the 'enga'gement between the tooth 48 and the tooth 37, continued rotation of the hand lever 31 in a clockwise direction will cause the helical-toothed pinion 34 to engage the longitudinalleg'44 of'the ll-shaped gear section 35,

i the longitudinal leg 44 of the gear section functioning 'as' a gear rack 'withWhe' pinion '34, to shift thelocking i i sleeve 5 forwardly (to the right when viewed'in Figures 1 and 3)'to uncover a'nd'clear "the breechblockexternal tl'ireads'52. Travel ofthe' sleeve 5 is terminated by the and the longitudinal leg" 44 'ofthe gear sector 35- are thus held against rotation and forward r'notionf However, as the hand lever '31and'consequently the helical toothed -pinion 34 are continued to be rotated in the clockwise' direction, vi'ew'ed'ir'i Figure lfthe'pinion 34 will'n'ow roll on the longitudinal leg 44 for the remainder of its length, carrying with it the gear case 32 and shafts 27 and 36 to the rear of the gun (to the left when viewed in Figures 3 and 4), overcoming the pressure of the spring-pressed detent 23, causing the same to ride out of the depression 29". The breechblock 4, being secured to the shaft 36, will likewise be moved rearwardly, separating it from the gun chamber 7, as shown in Figure 4, until the springpressed detent 23 rides into the transverse slot 29.

During this portion of the operating cycle, the operating hand lever 31 will have moved from its original position in Figure 1 approximately one complete revolution in a clockwise direction, coming to rest in a substantially vertical position shown by the dotted lines in Figure 4. In this position, the depending lug 31' is downward and clear of the flange 26' on the rearwardly-direc'ted inclined member 26 as shown in Fig. 8.

The operating hand lever 31 can now be swung downwardly and outwardly, in a clockwise direction when viewing Figure 8, rotating the shafts 27 and 36 and gear case 32 to tilt the breechblock 4 away from and downwardly of the gun, as shown by Figure 5, until completely clearing it.

When the shaft 36 is rotated, the radial projection on plate 38 abuts the periphery of the projection 51, thereby holding the sleeve 5 and the shaft 36 against further rotation and in a position for the gear leg 44 to be brought back into mesh with the pinion 34 when the breechblock 4 is tilted back toward gun chamber 7 (i. e., from the Figure 5 to the Figure 3 position) preparatory to being locked by the sleeve 5.

In the particular embodiment shown, the removal of the expended round and the insertion of a new one is accomplished manually, after which the operating lever P 31: is swungzupwardly; or counterclockwiseas in Figure .8,

: simultan'eou'slyicausingirotation of the-teeth 481and 49 -to pinion 84.

- Rotatingthe'1ever31 counterclockwise,- viewedin Figure 4 3; willecause the "spring-presseddetent-23- to ride out of theslot29' allowing the pinion-34 to' roll-along the longitudinal leg 44 of the gearsection 35 :until the breechblock 4 abuts the flange 9of-th'e chamber 7, as showndn Figure 3.

i Continued movement of the lever 3lin this counterclockwise direction will cause'the-pinion'34-to shift the sleeve 5 rearwardly until the enlarged part of the'slee've 5 covers'the breechblockexternalteeth 53, at which time the annular surface 47- will abut the collar 9 and thepinion will simultaneously engagethe transverse leg to" rotate the-sleeve causing intereng'agementbetween the interrupted teeth-52 and 53; as shownin Figure's 2 and 6,to lock -the breechblock- 4agains't'-the gun cham'ber3.

Although the preferred embodiment ha's been' disclosed,

it is obvious that-various modifications may-be made With- Qout departing from the 1 spirit andscope of the following claims:

I claim: 1. A-reco'illess artillery weapon comprising a g'un tube 1 having a' flanged chamber'andan externally threaded-portion'adjace'nt said chamber, atrunnion-band including' a generally cylindrical portion *in'threadedengatgemnt with -'-the thre'a'de-d portion of said-gun tube and a-longitudinally parallel bearing cylinder, key means for releasably locking -'and--angularly positioning'said band to said-tube; a cap forming a spaced closure for'one'end-of said bearing cylinder, a" spring pressed plungerprojecting-radially inwardly 35 t on said bearing cylinder intermediate its length, a locking sleeve including a generally cylindrical," shoulderedportion slidably and rotatably mounted for limited movement on said chamber and a locking ring integral with said sleeve and havingan interrupted -thread"therein; a' gen'eral-ly t shjaped rack formed-'on the outer-periphery of said 'shouldered-portion, an operating shaftassembly comprising a cylindrical part journaled in said bearing cylinder for limited axial and rotational movement relative thereto and having a plurality of grooves therein selectively engageable with said plunger, a breechblock mounting part, and an operating crank and helical pinion gear in mesh with said rack rotatably mounted between said breechblock. mounting part and cylindrical part, and a generally cylindrical breechblock secured to said mounting part and including a flanged portion adapted to abut the outer face of said chamber flange and having an external interrupted thread thereon, said locking sleeve being movable upon actuation of said crank, between two positions in one of which its interrupted thread engages that on said block and in the other of which said sleeve is disengaged and axially spaced from said block whereby the latter may be swung about said breechblock mounting part, by continued movement of said crank, into breech open position, and a quick detachable connection between said breechblock and its mounting part.

2. An artillery Weapon of the recoilless type comprising a gun tube having a flanged chamber and an externally threaded portion adjacent said chamber, a detachable trun nion band including a generally cylindrical portion in threaded engagement with a threaded portion of said gun tube and a longitudinally parallel bearing cylinder, key means for releasably locking said band to said tube, a cap forming a spaced closure for one end of said bearing cylinder, a spring pressed plunger projecting radially inwardly on said bearing cylinder intermediate its length, a locking sleeve including a generally cylindrical, shouldered portion slidably and rotatably mounted for limited movement on said chamber and an integral locking ring having an interrupted thread therein, a generally L-shaped rack formed on the outer periphery of said shouldered portion, an operating shaft assembly comprising a cylindrical part journaled in said bearing cylinder for limited axial and rotational movement relative thereto and having a plurality of grooves therein selectively engageable with said plunger, a breech mounting part, and an operating crank and helical pinion gear in mesh with said rack rotatably mounted between said breechblock mounting part and said cylindrical part, and a generally cylindrical breechblock secured to said mounting part and including a flanged portion adapted to abut the outer face of said chamber flange and having an external interrupted thread thereon said locking sleeve being movable upon actuation of said crank, between two positions in one of which its interrupted thread engages that on said block and in the other of which said sleeve is disengaged and axially spaced from said block whereby the latter may be swung, by continued movement of said crank, into breech open position.

3. An artillery weapon comprising a gun tube having a chamber and an externally threaded portion adjacent said chamber, a removable trunnion band including a generally cylindrical portion in threaded engagement with the threaded portion of said gun tube and a longitudinally parallel bearing cylinder, a locking sleeve including a generally cylindrical shouldered portion slidably and rotatably mounted for limited movement on said chamber and an integral locking ring having an interrupted thread therein,

. a generally L-shaped rack formed on the outer periphery of said shouldered portion, an operating shaft assembly comprising a cylindrical part journalled in said bearing cylinder for limited axial and rotational movement relative thereto, a breech mounting part, and an operating crank and helical pinion gear in mesh with said rack rotatably mounted between said parts, and a generally cylindrical breechblock secured to said mounting part and having an external interrupted thread thereon, said locking sleeve being movable, upon actuation of said crank, into at least two positions in one of which its interrupted thread engages that on said block, and in the other of which said sleeve is disengaged and axially spaced from said block whereby the latter may be swung, by continued movement of said crank, into open position, said breechblock having a quick detachable connection with said part on which it is mounted.

4. In a gun having a chamber and a breechblock movably mounted adjacent thereto and having locking means thereon, a mechanism for releasably locking said breechblock to said chamber comprising, a locking sleeve axially reciprocable and rotatable with respect to said chamber, locking means on said sleeve adapted to co-act with the locking means on said block, operating means movably mounted adjacent said chamber and adapted to be secured to said block, a helical pinion gear rotatably mounted on said operating means, and a generally L-shaped rack on said sleeve engaged with said pinion gear, said mechanism being constructed and arranged whereby initial rotation of said pinion gear rotates said sleeve to unlock the latter from the breech, further rotation of said pinion gear moves said sleeve a limited distance in an axial direction, and final continued rotation of said pinion gear moves said breechblock a limited distance in an opposite axial direction after movement of said sleeve has ceased.

References Cited in the file of this patent UNITED STATES PATENTS 1,108,716 Davis Aug. 25, 1914 1,215,255 Davison Feb. 6, 1917 1,272,293 Mirmillo July 9, 1918 1,311,021 Spear et a1. July 22, 1919 1,326,712 Dawson et a1. Dec. 30, 1919 1,335,500 Hasting Mar. 30, 1920 1,371,075 Dawson et a1. Mar. 8, 1921 1,394,490 Giles Oct. 18, 1921 1,395,630 Davis Nov. 1, 1921 1,434,044 Cooke Oct. 31, 1922 1,494,524 Adamson May 20, 1924 2,125,570 Ice Aug. 12, 1938 2,152,962 Ice Apr. 4, 1939 2,421,522 Pope June 3, 1947 FOREIGN PATENTS 89,970 Sweden Aug. 10, 1937 

